Sensor insertion device set and base plate

ABSTRACT

A sensor insertion assembly includes: a sensor insertion device comprising a needle member configured to be inserted in a living body together with a biological information sensor and to be pulled out of the living body after leaving a distal end side of the sensor in the living body; and a base plate detachably attached to a first end side of the sensor insertion device, the base plate comprising a clamp portion configured to move so as to clamp a proximal end side of the sensor extending to an outside of the living body after pulling out the needle member and along with an operation of detaching the sensor insertion device from the base plate.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a bypass continuation of PCT Application No.PCT/JP2015/005016, filed on Oct. 1, 2015, which claims priority toJapanese Application No. 2015-013734, filed on Jan. 27, 2015, thecontents of which are hereby incorporated by reference in theirentireties.

BACKGROUND

The present disclosure relates to a sensor insertion assembly (alsoreferred to as a “device set”) including a sensor insertion device and abase plate, and to the base plate for such a sensor insertion assembly.The sensor insertion device is configured to insert a sensor thatdetects biological information of a living body, such as a patient, intothe living body.

It is known to insert or embed a sensor in a body of a person to bemeasured, such as a patient, and detect an analyte (for example,glucose, pH, cholesterol, protein, etc.) in blood or body fluid of thepatient by using the sensor. In this case, a sensor insertion device isused for quickly and easily disposing the sensor through the skin of thepatient (see JP 2011-224381 A).

An analyte measurement system (sensor insertion assembly) described inPatent Literature 1 includes an applicator (sensor insertion device) andan attachment unit to be left on the living body surface side with thesensor. In addition, the applicator of JP 2011-224381 A includes aninsertion needle to be inserted with the sensor and a plungersub-assembly (movement mechanism) that moves the sensor and theinsertion needle to perform puncture.

SUMMARY

After leaving the sensor in the living body, the sensor is sometimesmoved in a direction in which the sensor is pulled out of the livingbody due to a body movement of the person to be measured or the like. Inthis case, there is a possibility that correct biological informationcannot be detected.

To address this, embodiments described herein aim to provide a sensorinsertion assembly and a base plate capable of making the sensor left inthe living body less likely to move in the pulling-out direction evenwith the body movement.

According to one embodiment, a sensor insertion assembly includes asensor insertion device including a needle member that is to be insertedin a living body together with a sensor capable of detecting biologicalinformation and is to be pulled out of the living body after leaving adistal end side of the sensor in the living body, and a base platedetachably attached to a first end side of the sensor insertion device,and the base plate includes a clamp portion that moves so as to clamp aproximal end side of the sensor extending to an outside of the livingbody after pulling out the needle member and along with an operation ofdetaching the sensor insertion device from the base plate.

According to one aspect, the clamp portion includes a pair of leafspring portions that clamp the proximal end side of the sensor, and thesensor insertion device is detachable from the base plate by beingrelatively rotated with respect to the base plate and includes a camportion capable of changing an engagement relationship with the pair ofleaf spring portions along with an operation of the rotating and therebychanging an amount of elastic deformation of the pair of leaf springportions.

According to one aspect, the pair of leaf spring portions include afirst leaf spring and a second leaf spring disposed so as to oppose thefirst leaf spring and having a larger spring constant than the firstleaf spring, and the base plate includes a position regulating portionthat regulates a position of the second leaf spring when being detachedfrom the sensor insertion device.

According to one aspect, an adhesive portion that adheres on a surfaceof the living body is provided on a surface of the base plate opposingthe surface of the living body.

According to one aspect, the sensor includes a detection portion that isto be left in the living body and is capable of detecting biologicalinformation and an optical fiber to a distal end portion of which thedetection portion is attached and which is to be left in the living bodyso as to extend to the outside of the living body.

According to another embodiment, a base plate is configured to bedetachably attached to a sensor insertion device that accommodates aneedle member that is to be inserted in a living body together with asensor capable of detecting biological information and is to be pulledout of the living body after leaving a distal end side of the sensor inthe living body, and includes a clamp portion that moves so as to clampa proximal end side of the sensor extending to an outside of the livingbody after pulling out the needle member and along with an operation ofrelatively rotating the base plate with respect to the sensor insertiondevice in a state of being attached to the sensor insertion device.

According to embodiments described herein, a sensor insertion assemblyand a base plate capable of making a sensor left in a living body lesslikely to move in a pulling-out direction even with body movement can beprovided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view of a sensor insertion assembly according to oneembodiment, and illustrates a state before inserting a sensor and aneedle member in a living body.

FIG. 2 illustrates a state in which the sensor and the needle member aremoved to a position at which the sensor and the needle member can beinserted in the living body after the state illustrated in FIG. 1.

FIG. 3 illustrates a state in which the needle member is moved to aposition at which the needle member can be pulled out of the living bodyafter the state illustrated in FIG. 2.

FIG. 4 is a perspective view of the sensor insertion assemblyillustrated in FIG. 1.

FIG. 5 is an enlarged section view in which the vicinity of the sensorand the needle portion is enlarged in the section view of the sensorinsertion assembly illustrated in FIG. 2.

FIG. 6 is an enlarged section view in which the vicinity of the sensorand the needle portion is enlarged in the section view of the sensorinsertion assembly illustrated in FIG. 3.

FIG. 7 illustrates a state in which a sensor insertion device and a baseplate are separated from each other after the state illustrated in FIG.3.

FIG. 8 is a perspective view of the sensor and the base plateillustrated in FIG. 7.

FIG. 9 is an exploded perspective view of the base plate illustrated inFIG. 8.

FIG. 10 illustrates an upper surface of the base plate attached to thesensor insertion device.

FIG. 11 illustrates an upper surface of the base plate in a state inwhich the base plate is detachable from the sensor insertion device.

FIG. 12 is an enlarged view of a center portion of the base plateillustrated in FIG. 11.

DETAILED DESCRIPTION

Exemplary embodiments of a sensor insertion assembly and a base platewill be described below with reference to FIGS. 1 to 12. Members commonto drawings are denoted with the same reference signs.

FIGS. 1 to 3 are section views of a sensor insertion assembly 100serving as an exemplary embodiment of the sensor insertion assemblyillustrating the configuration thereof. In addition, FIG. 4 is aperspective view of the sensor insertion assembly 100. The sensorinsertion assembly 100 includes a sensor insertion device 1 and a baseplate 2 serving as an exemplary embodiment of the base plate detachablyattached to a first end side of the sensor insertion device 1.

The sensor insertion assembly 100 inserts a sensor 50 in a living bodythrough a lower surface (a surface on the lower side in FIGS. 1 to 4) ofthe base plate 2 by operating the sensor insertion device 1 with thebase plate 2 placed on or pressed against the surface of the livingbody.

<Sensor Insertion Assembly 100>

<Sensor Insertion Device 1>

First, the sensor insertion device 1 in the sensor insertion assembly100 will be described. As illustrated in FIGS. 1 to 4, the sensorinsertion device 1 in the present exemplary embodiment inserts thesensor 50, which is capable of detecting biological information frombody fluid, in a living body. Specifically, the sensor insertion device1 includes a housing 3, a needle member 4, a first urging member 5, asecond urging member 6, a movable member 7, and an operation member 8.

Here, FIGS. 1 and 4 each illustrate the sensor insertion device 1 andthe sensor insertion assembly 100 in a state before the sensor 50 andthe needle member 4 are inserted in the living body, and FIG. 2illustrates the sensor insertion device 1 and the sensor insertionassembly 100 in a state in which the sensor 50 and the needle member 4is moved to a position at which the sensor 50 and the needle member 4can be inserted in the living body. In addition, FIG. 3 illustrates thesensor insertion device 1 and the sensor insertion assembly 100 in astate in which the needle member 4 is moved to a position at which theneedle member 4 can be pulled out of the living body after the sensor 50is left in the living body.

Each component of the sensor insertion device 1 according to the presentexemplary embodiment and a characteristic portion constituted by eachcomponent will be described in detail below.

[Housing 3]

As illustrated in FIGS. 1 to 4, the housing 3 includes a cylinderportion 3 a defining a hollow portion having a substantially cylindricalshape, a bottom plate portion 3 b provided on a first end side (thelower side in FIGS. 1 to 4) of the cylinder portion 3 a, and a top plateportion 3 c provided on a second end side (the upper side in FIGS. 1 to4) of the cylinder portion 3 a. The bottom plate portion 3 b ispositioned at a first end side of the hollow portion defined by thecylinder portion 3 a, and a through hole 9 through which a needleportion 11 of the needle member 4 that will be described later ismovable is defined therein. In addition, the top plate portion 3 c ispositioned at a second end side of the hollow portion defined by thecylinder portion 3 a, and a through hole 10 through which the movablemember 7 is movable is defined therein.

The bottom plate portion 3 b of the housing 3 includes an engagementportion 60 serving as a locking release portion configured to fit insidea cylinder portion 7 a having a cylindrical shape in the movable member7 that will be described late and engages with a deformation portion 7 cthat will be described later to deform the deformation portion 7 c tothe outside in the radial direction. More specifically, the engagementportion 60 according to the present exemplary embodiment is a projectionportion 60 a formed in a columnar shape on the upper surface of thebottom plate portion 3 b.

In addition, the bottom plate portion 3 b of the housing 3 includes acam portion 61 capable of changing the amount of elastic deformation ofa pair of leaf spring portions 32 by changing an engagement relationshipbetween the base plate 2 and the pair of leaf spring portions 32 thatwill be described later along with an operation of relatively rotatingwith respect to the base plate 2. More specifically, the cam portion 61according to the present exemplary embodiment is a projection portion 61a formed in an elliptical columnar shape on the lower surface of thebottom plate portion 3 b.

The cylinder portion 3 a and the top plate portion 3 c of the housing 3according to the present exemplary embodiment are constituted by acylindrical housing body, and the bottom plate portion 3 b according tothe present exemplary embodiment is constituted by a bottom plate memberattached and fixed to the housing body. Examples of a material for thehousing body and the bottom plate member constituting the housing 3include a resin material. Examples of the resin material includethermoplastic resins used for injection molding such as ABS resin, ASresin, polyethylene, polypropylene, polystyrene, polyvinyl chloride,polyvinylidene chloride resin, polyphenylene oxide, thermoplasticpolyurethane, polymethylene methacrylate, polyoxyethylene, fluorineresin, polycarbonate, polyamide, acetal resin, acrylic resin, andpolyethylene terephthalate, and thermosetting resins such as phenolresin, epoxy resin, silicone resin, and unsaturated polyester.

[Needle Member 4]

As illustrated in FIGS. 1 to 4, the needle member 4 includes the needleportion 11 that is to be inserted in a living body with the sensor 50, aconnection portion 12 positioned on the proximal end side of the needleportion 11 and connected to a retrieving spring 6 a serving as thesecond urging member 6 that will be described later, and a lockedportion 13 locked by a projection portion 18 serving as a lockingportion of the movable member 7 that will be described later, and ismovable in the housing 3 in a insertion direction A of the needleportion 11 and in a pulling-out direction B in which the needle portion11 is pulled out of the living body.

Here, the insertion direction A of the needle portion 11 corresponds toa direction from the proximal end to the distal end of the needleportion 11 in the direction in which the needle portion 11 extends, andcorresponds to a downward direction in FIGS. 1 to 4. By contrast, thepulling-out direction B of the needle portion 11 corresponds to adirection from the distal end to the proximal end of the needle portion11 in the direction in which the needle portion 11 extends, andcorresponds to an upward direction in FIGS. 1 to 4. The direction inwhich the needle portion 11 extends is the same direction as thedirection of a center axis line of the needle portion 11 in the presentexemplary embodiment. In addition, the insertion direction A may bedescribed simply as “downward direction” and the pulling-out direction Bmay be described simply as “upward direction” below, and these mean thesame thing defined herein.

The needle portion 11 of the present exemplary embodiment has acylindrical external shape defining a hollow portion, and is capable ofaccommodating the sensor 50 in the hollow portion. The needle portion 11is inserted in a living body with the sensor 50 accommodated in thehollow portion, and is pulled out of the living body after leaving thesensor 50 in the living body. The needle portion 11 of the presentexemplary embodiment is constituted by a hollow cylindrical needle.

As a material for the hollow cylindrical needle constituting the needleportion 11, metal materials such as stainless steel, aluminum, aluminumalloy, titanium, and titanium alloy may be exemplarily used. Inaddition, a sharp cutting edge is formed in the distal end of the needleportion 11.

The connection portion 12 of the present exemplary embodiment has asubstantially cylindrical shape in which a through hole 14 is defined,and a spiral groove in which the retrieving spring 6 a serving as thesecond urging member 6 is locked is defined on the outer surfacethereof.

The locked portion 13 of the present exemplary embodiment is a flangeportion projecting from a lower end portion of the cylindricalconnection portion 12 outward in the radial direction, and the needlemember 4 is locked with respect to the movable member 7 as a result ofan outer edge portion of the flange portion being engaged with andstopped by the projection portion 18 serving as a locking portion of themovable member 7. The details will be described later.

The connection portion 12 and the locked portion 13 of the presentexemplary embodiment are constituted by a needle supporting member towhich the hollow cylindrical needle constituting the needle portion 11is fixed and which supports the hollow cylindrical needle. Specifically,the needle supporting member and the hollow cylindrical needle areengaged with each other such that an inner peripheral surface definingthe through hole 14 of the connection portion 12 is in firm contact withthe outer peripheral surface of a proximal end portion of the hollowcylindrical needle, and thus the hollow cylindrical needle is fixed tothe needle supporting member.

The needle member is not limited to a needle member constituted by ahollow cylindrical needle and a needle supporting member as the needlemember 4 of the present exemplary embodiment. For example, a needleportion, a connection portion, and a locked portion may be integrallyformed as a single member. Further, a needle portion, a connectionportion, and a locked portion may be constituted by three or moremembers.

As a material for the needle supporting member constituting theconnection portion 12 and the locked portion 13, resin materials thatcan be used for the housing 3 described above, metal materials that canbe used for the needle portion 11 described above, and so forth can beused.

[First Urging Member 5 and Second Urging Member 6]

The first urging member 5 is capable of urging the needle member 4 inthe insertion direction A to move the needle member 4 to a firstposition (see FIG. 2) at which the needle portion 11 can be inserted inthe living body. In addition, the second urging member 6 is capable ofurging the needle member 4 in the pulling-out direction B to move theneedle member 4 to a second position (see FIG. 3) at which the needleportion 11 that has reached the first position (see FIG. 2) can bepulled out of the living body.

The first urging member 5 and the second urging member 6 of the presentexemplary embodiment are both elastic members (hereinafter an elasticmember serving as the first urging member 5 will be described as “afirst elastic member”, and an elastic member serving as the secondurging member 6 will be described as “a second elastic member”). Springsare used as the first elastic member and the second elastic member inthe present exemplary embodiment. Hereinafter, the spring serving as thefirst elastic member will be simply described as “a insertion spring 5a”, and the spring serving as the second elastic member will be simplydescribed as “the retrieving spring 6 a”. Further, in the presentexemplary embodiment, coil springs are used as the insertion spring 5 aand the retrieving spring 6 a.

Here, the first elastic member serving as the first urging member 5 andthe second elastic member serving as the second urging member 6 of thepresent exemplary embodiment are arranged in series in the insertiondirection A (or the pulling-out direction B). The movement of the needlemember 4 in the insertion direction A (see FIGS. 1 and 2) is caused byan urging force of the first urging member 5 (in the present exemplaryembodiment. An elastic force (restoring force) of the retrieving spring6 a serves as the second elastic member) without contribution of anurging force of the second urging member 6 (in the present exemplaryembodiment, an elastic force (restoring force) of the insertion spring 5a serving as the first elastic member). In addition, the movement of theneedle member 4 in the pulling-out direction B (see FIGS. 2 and 3) iscaused by the urging force of the second urging member 6 withoutcontribution of the urging force of the first urging member 5. Thesensor insertion device 1 of the present exemplary embodiment includes aswitching mechanism for realizing these operations. The switchingmechanism will be described later.

[Movable Member 7]

The movable member 7 can be moved in the housing 3 in the insertiondirection A by the urging force of the first urging member 5 (in thepresent exemplary embodiment, the elastic force of the insertion spring5 a that has been compressed). Specifically, the movable member 7includes a locking claw portion 15 serving as a locking portion that iscapable of engaging with the housing 3 in a state where the insertionspring 5 a is compressed to a predetermined length and thus retainingthe position of the movable member 7 with respect to the housing 3, anda receiving portion 16 that comes into contact with the insertion spring5 a serving as the first urging member 5 to be pressed in the insertiondirection A.

As illustrated in FIGS. 1 to 3, the insertion spring 5 a is disposedbetween the movable member 7 and the top plate portion 3 c of thehousing 3. And the insertion spring 5 a can be compressed by moving themovable member 7 in the housing 3 in the pulling-out direction B againstthe elastic force of the insertion spring 5 a. Then, the movable member7 can be locked with respect to the housing 3 by engaging a claw 21 ofthe locking claw portion 15 with the top plate portion 3 c of thehousing 3 in a state where the insertion spring 5 a is compressedbetween the movable member 7 and the housing 3 (see FIG. 1). That is,the movable member 7 is locked with respect to the housing 3 by thelocking claw portion 15 in a state where the first urging member 5retains energy (in the present exemplary embodiment, energy of therestoring force of the insertion spring 5 a that has been compressed) tomove the movable member 7 in the insertion direction A. Inclusion ofsuch a structure enables compressing the insertion spring 5 a in advanceat the time of production. That is, inclusion of such a structureenables saving time and effort of a patient or a health care worker tocharge the insertion spring 5 a.

Then, the engagement between the housing 3 and the locking claw portion15 of the movable member 7 is released by operating a pressing plateportion 23 of the operation member 8 that will be described later, andthe movable member 7 is moved in the housing 3 in the insertiondirection A by the elastic force of the insertion spring 5 a pressingthe receiving portion 16.

In addition, the needle member 4 is connected to the movable member 7via the retrieving spring 6 a serving as the second urging member 6, andthe movable member 7 is capable of moving in the housing 3 in theinsertion direction A due to the elastic force of the insertion spring 5a while retaining a state where the elastic force of the retrievingspring 6 a expanded to a predetermined length is applied to the needlemember 4. Specifically, the movable member 7 includes a connectionportion 17 connected to an upper end portion of the retrieving spring 6a and the projection portion 18 serving as a locking portion that iscapable of locking the needle member 4 connected to a lower end portionof the retrieving spring 6 a in a state where the retrieving spring 6 ais expanded to the predetermined length.

That is, the retrieving spring 6 a is connected to the connectionportion 12 of the needle member 4 and the connection portion 17 of themovable member 7, and is not connected to the housing 3. Accordingly,the movable member 7 can be moved in the insertion direction A by theelastic force of the insertion spring 5 a while the state where theretrieving spring 6 a is expanded to the predetermined length isretained by the projection portion 18.

Further, in the present exemplary embodiment, the movable member 7 ismoved in the insertion direction A by the urging force (in the presentexemplary embodiment, the elastic force of the insertion spring 5 a) ofthe first urging member 5, and, when the needle member 4 reaches thefirst position (see FIG. 2), the locked state of the needle member 4derived from the projection portion 18 is released by the engagementportion 60 of the housing 3 serving as a locking release portion.Accordingly, the needle member 4 is moved to the second position (seeFIG. 3) in the pulling-out direction B by the urging force (in thepresent exemplary embodiment, the elastic force of the retrieving spring6 a) of the second urging member 6.

Further, the movable member 7 includes a rod portion 19 having astraight line shape and inserted in the needle portion 11 from theproximal end side of the needle portion 11 through the through hole 14of the connection portion 12 of the needle member 4. This rod portion 19presses the sensor 50 in the insertion direction A in the needle portion11 when pulling out the needle portion 11 in a state where the sensor 50is left in the living body after the needle portion 11 and the sensor 50in the needle portion 11 are inserted in the living body. This preventsthe sensor 50 from being pulled out together with the needle portion 11.

A detailed configuration of the movable member 7 of the presentexemplary embodiment will be described below. The movable member 7 ofthe present exemplary embodiment includes a cylinder portion 7 a havinga cylindrical shape that surrounds the needle member 4 and theretrieving spring 6 a serving as the second urging member 6, a flangeportion 7 b provided on a first end of on the lower side of the cylinderportion 7 a so as to project outward in the radial direction, a leafspring portion (see FIG. 4) serving as the deformation portion 7 c thatis positioned at an end portion of the cylinder portion 7 a in theinsertion direction A, is interposed in a cutout 20 in a circumferentialdirection D of the cylinder portion 7 a, and is capable of beingelastically deformed outward in the radial direction of the cylinderportion 7 a, a top plate portion 7 d provided at an end on the upperside of the cylinder portion 7 a, the locking claw portion 15 that isprovided on an upper surface of the top plate portion 7 d so as toproject in the pulling-out direction B and includes, at the distal endthereof, the claw 21 configured to engage with the top plate portion 3 cof the housing 3, the receiving portion 16 that is provided on an outersurface of the cylinder portion 7 a so as to project outward in theradial direction and comes into contact with the insertion spring 5 a,the connection portion 17 which is provided below the top plate portion7 d and in the outer surface of which a spiral groove for locking theretrieving spring 6 a is defined, and the rod portion 19 which extendsfrom the connection portion 17 in the insertion direction A and a distalend portion of which is inserted in the needle portion 11 of the needlemember 4.

As illustrated in FIGS. 1 to 3, the projection portion 18, serving as alocking portion described above, is formed on the inner wall of thedeformation portion 7 c and projects in a hollow portion defined by thecylinder portion 7 a of the movable member 7. Therefore, the deformationportion 7 c of the movable member 7 engages with the projection portion60 a having a columnar shape serving as the engagement portion 60 formedon the bottom plate portion 3 b located at the end portion of thehousing 3 in the insertion direction A and is elastically deformed so asto expand outward in the radial direction of the cylinder portion 7 awhen the needle member 4 reaches the first position (see FIG. 2).Accordingly, the projection portion 18 formed on the inner wall of thedeformation portion 7 c is also moved outward in the radial direction,and thus the locked state of the projection portion 18 serving as thelocking portion of the movable member 7 and the flange portion servingas the locked portion 13 of the needle member 4 is released and theneedle member 4 is moved in the cylinder portion 7 a in the pulling-outdirection B by the elastic force of the retrieving spring 6 a (see FIG.3).

Here, the outer diameter of the cylindrical projection portion 60 a ofthe housing 3 is formed to be substantially equal to the inner diameterof the cylinder portion 7 a of the movable member 7, and a projection22, which converts a pressing force applied from the projection portion60 a in the pulling-out direction B into a pressing force outward in theradial direction of the cylinder portion 7 a while sliding on the outerwall of the projection portion 60 a when the projection portion 60 afits inside the cylinder portion 7 a, is formed on the inner wall of thedeformation portion 7 c. Specifically, a lower surface 22 a of theprojection 22 is inclined with respect to a center axis line O (in thepresent exemplary embodiment, coincides with a center axis line of theneedle portion 11) of the cylinder portion 7 a such that the lowersurface 22 a approaches the center axis line O as the lower surface 22 aadvances in the pulling-out direction B, and the outer peripheralsurface of the projection portion 60 a elastically deforms the leafspring portion serving as the deformation portion 7 c outward in theradial direction while sliding on the lower surface 22 a of theprojection 22 (see FIG. 2, etc.).

The movement of the movable member 7 caused by the elastic force of theinsertion spring 5 a is configured so as to be guided in the insertiondirection A as a result of the outer peripheral surfaces of the flangeportion 7 b and the receiving portion 16 of the movable member 7 slidingon the inner peripheral surface of the cylinder portion 3 a of thehousing 3. In addition, as illustrated in FIGS. 1 to 3, the rod portion19 is surrounded by the retrieving spring 6 a and extends from theconnection portion 17 in the insertion direction A, and the distal endportion thereof reaches the needle portion 11 through the connectionportion 12 of the needle member 4.

The cylinder portion 7 a, the flange portion 7 b, the deformationportion 7 c, the top plate portion 7 d, the locking claw portion 15, andthe receiving portion 16 of the movable member 7 of the presentexemplary embodiment are constituted by a single cylindrical body thathas been formed as one piece. In addition, the connection portion 17 ofthe movable member 7 of the present exemplary embodiment is constitutedby a connection member fastened to the top plate portion 7 d of thecylindrical body by fastening means such as bolts or screws. Further,the rod portion 19 of the movable member 7 of the present exemplaryembodiment is constituted by a rod member whose proximal end portion isfixed to the connection member constituting the connection portion 17.In the present exemplary embodiment, the connection member constitutingthe connection portion 17 includes a cylinder portion on the outerperipheral surface of which a spiral groove capable of locking theretrieving spring 6 a is defined, and the proximal end portion of therod member constituting the rod portion 19 is fixed with respect to theconnection member in a state of being inserted in the cylinder portionof the connection member.

However, the above-described portions of the movable member are notlimited to portions constituted by the cylinder body, the connectionmember and the rod member as the present exemplary embodiment. Forexample, all the portions of the movable member described above may beconstituted by one or two members, or may be constituted by four or moremembers.

As an example of this, the cylinder body described above can be formedby connecting molded resin parts equally divided into three in thecircumferential direction of the cylinder portion 7 a via a connectionmethod such as gluing or fusing. By using such a production method,complication of a mold can be suppressed.

Although three locking claw portions 15 are provided on the movablemember 7 of the present exemplary embodiment, the number thereof is notlimited to this and may be 1, 2, or 4 or more. Further, the shape andposition of the locking claw portion 15 is not limited to theconfiguration of the present exemplary embodiment, and may be changed asappropriate. Further, the number, position, and shape of the leaf springportion serving as the deformation portion 7 c is not limited to theconfiguration of the present exemplary embodiment, and may be changed asappropriate in accordance with the number, position, and shape ofengagement portions that deforms the deformation portion.

As a material for the cylinder body, connection member, and rod memberconstituting the movable member 7 of the present exemplary embodiment,resin materials that can be used for the housing 3 described above,metal materials that can be used for the needle portion 11 describedabove, and so forth can be used. However, it is preferable that thecylinder body is formed of a resin material that can be used for thehousing 3 described above, and it is preferable that the connectionmember and the rod member are formed of metal materials that can be usedfor the needle portion 11 described above.

[Operation Member 8]

As illustrated in FIGS. 1 to 4, the operation member 8 of the presentexemplary embodiment includes the pressing plate portion 23 of acircular plate shape configured to be operated by an user such as apatient or a health care worker, a projection portion 25 that includes aclaw 24 that is formed on an lower surface of the pressing plate portion23 and configured to be inserted in the housing 3 through the throughhole 10 of the top plate portion 3 c of the housing 3 and engage with alower surface of the top plate portion 3 c, and a pressing portion 26that is formed on the lower surface of the pressing plate portion 23 andserves as a locking release portion capable of releasing the lockedstate of the movable member 7 with respect to the housing 3 by pressingand deforming the locking claw portion 15 of the movable member 7.

The claw 24 of the projection portion 25 is capable of engaging with thelower surface of the top plate portion 3 c of the housing 3 such thatthe operation member 8 is not dropped as a result of being pulled out inthe pulling-out direction B, and this suppresses pulling out anddropping of the operation member 8.

The pressing portion 26 includes a tapered portion 27 that is inclinedwith respect to the center axis line O of the cylinder portion 7 a ofthe movable member 7 such that the tapered portion 27 approaches thecenter axis line O as the tapered portion 27 advances in the insertiondirection A. When the pressing plate portion 23 is pressed down in theinsertion direction A, moves in the insertion direction A with thepressing plate portion 23 through the through hole 10 of the top plateportion 3 c. At this time, the tapered portion 27 of the pressingportion 26 presses the locking claw portion 15 of the movable member 7outward in the radial direction of the cylinder portion 7 a.Accordingly, the locking claw portion 15 deforms to the outside in theradial direction, and the engagement with the top plate portion 3 c ofthe housing 3 is released. As a result of this, the engagement state ofthe movable member 7 with respect to the housing 3 is released.

As a material for the operation member 8 of the present exemplaryembodiment, a resin material that can be used for the housing 3described above can be used.

[Sensor 50 to Be Attached to Sensor Insertion Device 1]

FIG. 5 is an enlarged section view of the vicinity of the needle portion11 and the sensor 50 of the sensor insertion assembly 100 illustrated inFIG. 2, and FIG. 6 is an enlarged section view of the vicinity of theneedle portion 11 and the sensor 50 of the sensor insertion assembly 100illustrated in FIG. 3.

As illustrated in FIG. 5, the sensor 50 projects downward through aninsertion hole 70 of the base plate 2 in a state of being accommodatedin the hollow portion of the needle portion 11 that is constituted by ahollow cylindrical needle. Therefore, the sensor 50 and the needleportion 11 can be inserted in the living body by placing or pressing thelower surface of the base plate 2 of the sensor insertion assembly 100in the state illustrated in FIG. 1 on or against the surface (skin) ofthe living body and operating the sensor insertion device 1 in thisstate to release the insertion spring 5 a described above (see FIGS. 2and 5). FIGS. 2 and 5 illustrate states where the needle member 4 is atthe first position. In addition, a rubber member 71 serving as a septumwhich the needle portion 11 can pierce through and be pulled out throughis fit in the insertion hole 70 of the base plate 2 of the presentexemplary embodiment. This further suppresses the risk of bacteria orthe like getting into the living body from the upper surface side of thebase plate 2 through the insertion hole 70 of the base plate 2 and apuncture formed in the surface of the living body by the insertion ofthe needle portion 11 and causing infection.

The sensor 50 includes a detection portion (not illustrated) that is tobe left in the living body and is capable of detecting biologicalinformation, and an optical fiber 51 to the distal end of which thedetection portion is attached and which is to be left in the living bodyto extend to the outside of the living body, and the needle portion 11is inserted in the living body in a state where both of the detectionportion and the optical fiber 51 are accommodated in the hollow portionof the needle portion 11.

Then, in the state illustrated in FIG. 5, the elastic force of theretrieving spring 6 a starts the movement of the needle member 4 in thepulling-out direction B due to an action of the switching mechanism thatwill be described later. However, as illustrated in FIG. 6, although theneedle portion 11 moves in the pulling-out direction B, the sensor 50does not move in the pulling-out direction B because the rod portion 19presses the sensor 50. Thus, it becomes possible to leave the sensor 50at a predetermined depth in the living body.

Further, after leaving the sensor 50 and pulling out the needle portion11 by using the sensor insertion assembly 100, the sensor insertiondevice 1 is detached in a state where the base plate 2 is left on theliving body side with the sensor 50. This enables connecting, to aportion of the optical fiber 51 of the sensor 50, which has been left,on the proximal end side that extends to the outside, a processingdevice constituted by an optical detection portion including anirradiation portion that irradiates the detection portion withexcitation light and a light receiving portion that receives fluorescentlight obtained from the detection portion in accordance with the amountof analyte, and a processing portion that processes signals obtainedfrom the optical detection portion and the optical detection portion.Accordingly, the optical fiber 51 constitutes a transmission paththrough which the biological information detected by the detectionportion is transmitted to the processing device. The processing devicemay be designed as appropriate in accordance with the object and usethereof, for example, as a memory that stores the biologicalinformation, a transmitter that transmits the biological information toan external device, or a display monitor that displays the biologicalinformation.

Although states where the sensor 50 is located in the needle portion 11of the needle member 4 are shown for the sensor insertion device 1 ofthe present exemplary embodiment illustrated in FIGS. 1 to 3, the sensor50 according to the present exemplary embodiment is not a constituent ofthe sensor insertion device 1 but a disposable item that can bedetachably attached to the sensor insertion device 1 and used only once.Alternatively, the sensor maybe configured as a constituent of thesensor insertion device, and the whole of the sensor insertion deviceincluding the sensor may be configured as a disposable item. Further,although the needle member 4 of the present exemplary embodiment isconfigured to be undetachable from the sensor insertion device 1, theneedle member may be detachable from the sensor insertion device andconfigured as a detachable unit that can be used as a disposable item.

In addition, although a sensor including an optical fiber is used as thesensor 50 in the present exemplary embodiment, a sensor that includes alead connected to the detection portion left in the living body andextends to the outside of the living body and an electrical connectionportion provided at a proximal end portion of the lead for connectionwith the processing device may be used. However, in the case where thesensor 50 including the optical fiber 51 as in the present exemplaryembodiment is used, one having a cylindrical outer shape defining ahollow portion maybe used as the needle portion 11 of the needle member4 because the electrical connection portion described above does notneed to be provided. The needle portion 11 having such a cylindricalouter shape is easily produced compared with a U-shaped needle having aU-shape in cross section in which a gap is provided so as to let anelectrical connection portion extend to the outside of the needleportion, and thus it is beneficial to be able to employ a needle portionhaving a circular shape in cross section as in the present exemplaryembodiment.

[Switching Mechanism]

The sensor insertion device 1 of the present exemplary embodimentincludes a switching mechanism that is capable of performing selectiveswitching from moving the needle member 4 in the insertion direction Aby the urging force (in the present exemplary embodiment, restoringforce of the insertion spring 5 a that has been compressed) of the firsturging member 5 to moving the needle member 4 in the pulling-outdirection B by the urging force (in the present exemplary embodiment,restoring force of the retrieving spring 6 a that has been expanded) ofthe second urging member 6 when the needle member 4 reaches the firstposition (see FIG. 2).

Here, “selective switching” means that switching is performed such thatthe movement of the needle member 4 to the first position at the time ofinsertion and the movement of the needle member 4 to the second positionat the time of pulling out are performed under the influence ofdifferent urging members. In the present exemplary embodiment,“selective switching” means that switching is performed between themovement of the needle member 4 at the time of insertion performed underthe influence of the restoring force of the insertion spring 5 a withoutthe influence of the restoring force of the retrieving spring 6 a andthe movement of the needle member 4 performed at the time of pulling outperformed under the influence of the restoring force of the retrievingspring 6 a without the influence of the restoring force of the insertionspring 5 a.

Specifically, the switching mechanism of the present exemplaryembodiment is constituted by the projection portion 18 serving as alocking portion of the movable member 7 and the projection portion 60 ahaving an columnar shape that is an engagement portion serving as alocking release portion of the housing 3.

As described above, the projection portion 18 serving as the lockingportion of the movable member 7 is configured to lock the needle member4 by retaining the state where the elastic force (restoring force) ofthe retrieving spring 6 a that has been expanded is applied to theneedle member 4, and is formed on the inner wall of the deformationportion 7 c. In addition, the projection portion 60 a serving as thelocking release portion of the housing 3 is configured to release thelocked state of the needle member 4 deriving from the projection portion18 serving as the locking portion of the movable member 7 when theneedle member 4 reaches the first position (see FIG. 2), and thisprojection portion 60 a is formed on the bottom plate portion 3 b andengages with the projection 22 of the deformation portion 7 c to deformthe deformation portion 7 c to the outside in the radial direction whenthe needle member 4 reaches the first position. Accordingly, the needlemember 4 is moved in the pulling-out direction B by the restoring forceof the retrieving spring 6 a without moving the movable member 7 in thehousing 3, and is accommodated in the movable member 7, specifically, inthe cylinder portion 7 a of the movable member 7. In other words, theneedle member 4 is moved to the second position (see FIG. 3) by therestoring force of the retrieving spring 6 a.

The sensor insertion device 1 of the present exemplary embodiment iscapable of automatically performing the insertion of the sensor 50 andthe needle portion 11 in the living body by the urging force of theinsertion spring 5 a serving as the first urging member 5 andpulling-out of the needle portion 11 to the outside of the living bodyby the urging force of the retrieving spring 6 a serving as the secondurging member 6 in a coordinated manner without intervention of a manualoperation by a user just performing an operation of pressing down thepressing plate portion 23 of the operation member 8, and thus is capableof shortening the time in which the needle portion 11 is present in theliving body. Thus, the pain that the person to be measured in which thesensor 50 is to be left feels during a period from the insertion to thepulling-out of the needle portion 11 can be alleviated.

Further, because the sensor insertion device 1 of the present exemplaryembodiment includes the switching mechanism described above, the urgingforce (in the present exemplary embodiment, elastic force of theretrieving spring 6 a) of the second urging member 6 does not act so asto reduce the insertion speed in the insertion direction A at the timeof inserting the sensor 50 and the needle portion 11, and, moreover, theurging force (in the present exemplary embodiment, elastic force of theinsertion spring 5 a) of the first urging member 5 does not act so as toreduce the pulling-out speed in the pulling-out direction B at the timeof pulling out the needle portion 11. Accordingly, the sensor insertiondevice 1 of the present exemplary embodiment makes it easier to realizea configuration to accelerate the insertion speed of the sensor 50 andthe needle portion 11 and the pulling-out speed of the needle portion 11compared with a sensor insertion device that does not include aswitching mechanism like the present exemplary embodiment, that is, asensor insertion device in which the elastic force of a retrievingspring acts so as to reduce the insertion speed and the elastic force ofa insertion spring acts so as to reduce the pulling-out speed.

<Base Plate 2>

Next, the base plate 2 will be described. As described above, the sensorinsertion assembly 100 includes the sensor insertion device 1 describedabove and the base plate 2 detachably attached to a first end of thesensor insertion device 1. FIG. 7 illustrates a state where the sensorinsertion device 1 and the base plate 2 are separated by relativelyrotating the sensor insertion device 1 and the base plate 2 with respectto each other after the state illustrated in FIG. 3.

The base plate 2 is used with the sensor insertion device 1 wheninserting and leaving the sensor 50 in the living body (see FIGS. 1 to3, etc.), and is separated from the sensor insertion device 1 and lefton the living body side with the sensor 50 after leaving the sensor 50in the living body (see FIG. 7).

The base plate 2 separated from the sensor insertion device 1 and lefton the surface (skin) of the living body is used as a supporting memberof the processing device. That is to say, the base plate 2 is a memberto which the processing device connected to the proximal end portion ofthe optical fiber 51 of the sensor 50 can be attached.

In other words, the base plate 2 is detachably attached to the sensorinsertion device 1 that accommodates the needle member 11 that is to beinserted in the living body with the biological information sensor 50and pulled out of the living body after leaving the distal end side ofthe sensor 50 in the living body.

FIG. 8 is a perspective view of the sensor 50 and the base plate 2 in astate of being left on the living body side, and FIG. 9 is an explodedperspective view of the base plate 2. In addition, FIG. 10 illustratesan upper surface of the base plate 2 in a state of being attached to thesensor insertion device 1, that is, in a state illustrated in FIGS. 1 to6, and FIG. 11 illustrates the upper surface of the base plate 2 in astate of being detachable from the sensor insertion device 1, that is,in a state illustrated in FIG. 7. In FIGS. 10 and 11, the configurationof a bottom plate member constituting the bottom plate portion 3 b ofthe housing 3 of the sensor insertion device 1 is indicated by brokenlines for the sake of convenience of description.

The state where the base plate 2 is attached to the sensor insertiondevice 1 indicates a state where the base plate 2 and the sensorinsertion device 1 cannot be separated even if the whole of the sensorinsertion device 1 is moved in the pulling-out direction B with respectto the base plate 2. In addition, the state where the base plate 2 isdetachable from the sensor insertion device 1 indicates a state wherethe base plate 2 can be separated from the sensor insertion device 1 bymoving the sensor insertion device 1 in the pulling-out direction B withrespect to the base plate 2.

As illustrated in FIGS. 8 to 11, the base plate 2 of the presentexemplary embodiment includes a clamp portion 28 capable of clamping thesensor 50, joint portions 29 that change the engagement relationshipwith the bottom plate portion 3 b of the housing 3 of the sensorinsertion device 1 between the attached state and the detachable stateof the base plate 2 and the sensor insertion device 1, a positionregulating portion 30 that regulates the position of the clamp portion28, and a adhesive portion 31 that can be stuck on the surface of theliving body.

In addition, the base plate 2 of the present exemplary embodimentfurther includes a plate body portion 2 a having a circular plate shapeand a peripheral wall portion 2 b formed continuously from the outeredge of the plate body portion 2 a. The clamp portion 28 and theposition regulating portion 30 are provided at a center portion of theupper surface of the plate body portion 2 a, and the joint portions 29are provided at outer peripheral portions of the upper surface of theplate body portion 2 a. Further, the adhesive portion 31 is provided onthe lower surface side of the plate body portion 2 a. As illustrated inFIGS. 9 and 10, the insertion hole 70 through which the needle portion11 (see FIGS. 1 to 7) of the sensor insertion device 1 and the sensor 50can pass is defined in the plate body portion 2 a, and the base plate 2further includes the rubber member 71 serving as the septum which blocksthe insertion hole 70 and which the needle portion 11 and the sensor 50can pierce through and be pulled out through.

The clamp portion 28 moves, along with an operation of detaching thesensor insertion device 1 from the base plate 2 performed in the statewhere the sensor insertion device 1 and the base plate 2 are attached,so as to clamp the proximal end side of the sensor 50 left on the livingbody side after pulling out the needle member 4, the proximal end sideextending to the outside of the living body. More specifically, thesensor insertion device 1 according to the present exemplary embodimentcan be detached from the base plate 2 by being relatively rotated withrespect to the base plate 2, and the clamp portion 28 according to thepresent exemplary embodiment moves, along with the rotating operation,so as to clamp the proximal end side of the sensor 50 left on the livingbody side after pulling out the needle member 4, the proximal end sideextending to the outside of the living body.

More specifically, the clamp portion 28 of the present exemplaryembodiment includes the pair of leaf spring portions 32 that clamp theproximal end side of the sensor 50 by an elastic force in aperpendicular direction C (in a state where the base plate 2 is attachedto the sensor insertion device 1, a direction same as a directionperpendicular to the insertion direction A and the pulling-out directionB) perpendicular to the thickness direction of the plate body portion 2a and spring regulating portions 33 that regulate movement of the pairof leaf spring portions 32 in the thickness direction of the plate bodyportion 2 a, and the pair of leaf spring portions 32 are configured tochange the form thereof, due to the effect of the projection portion 61a having an elliptic columnar shape and serving as the cam portion 61 ofthe sensor insertion device 1, between a state where the sensorinsertion device 1 and the base plate 2 are attached (see FIG. 10) and astate where the sensor insertion device 1 and the base plate 2 are in adetachable positional relationship (see FIG. 11). In other words, alongwith an operation (in the present exemplary embodiment, the operation ofrelatively rotating the sensor insertion device 1 with respect to thebase plate 2) of detaching the sensor insertion device 1 from the baseplate 2 performed in the state where the sensor insertion device 1 andthe base plate 2 are attached, the projection portion 61 a serving asthe cam portion 61 changes the amount of elastic deformation of the pairof leaf spring portions 32 by changing the engagement relationship withthe pair of leaf spring portions 32.

As illustrated in FIG. 10, the pair of leaf spring portions 32 are, inthe state where the sensor insertion device 1 and the base plate 2 areattached, elastically deformed such that an opposing distance Mtherebetween is made longer by the projection portion 61 a having anelliptic columnar shape serving as the cam portion 61. Specifically, thepair of leaf spring portions 32 are, in the state where the sensorinsertion device 1 and the base plate 2 are attached, pressed torespective sides across a longitudinal direction by an outer surface ofthe projection portion 61 a opposing in the longitudinal direction suchthat the pair of leaf spring portions 32 are moved away from each other,and elastically deformed such that the opposing distance M of portionsclamping the sensor 50 is made longer. Therefore, the pair of leafspring portions 32 does not clamp the sensor 50 in the state where thesensor insertion device 1 and the base plate 2 are attached (see FIG.10).

Accordingly, a state where the opposing distance M of the pair of leafspring portions 32 is made longer by the projection portion 61 a isretained at the time of an operation of inserting the sensor 50 and theneedle portion 11 and leaving the sensor 50 performed by the sensorinsertion assembly 100 as illustrated in FIGS. 1 to 3, and thus the pairof leaf spring portions 32 does not come into contact with the sensor 50and the needle portion 11. Therefore, the operation of inserting theneedle portion 11 and the sensor 50 through the insertion hole 70 of thebase plate 2 is not hindered by the pair of leaf spring portions 32 ofthe clamp portion 28.

In contrast, in the case where the sensor insertion device 1 is rotatedin one direction of a circumferential direction D (see a thick arrow inFIG. 10) with respect to the base plate 2 in the state where the sensorinsertion device 1 and the base plate 2 are attached (see FIG. 10), theprojection portion 61 a also rotates in the same direction (onedirection of the circumferential direction D) with respect to the baseplate 2 along with this operation. Therefore, the engagementrelationship between the projection portion 61 a serving as the camportion 61 and the pair of leaf spring portions 32 changes from thestate where the sensor insertion device 1 and the base plate 2 areattached (see FIG. 10).

Specifically, although the pair of leaf spring portions 32 are pressedby the outer surface of the projection portion 61 a opposing in thelongitudinal direction in the state where the sensor insertion device 1and the base plate 2 are attached (see FIG. 10), the pair of leaf springportions 32 are not in contact with the outer wall of the projectionportion 61 a in a state where the base plate 2 is moved to the positionat which the base plate 2 can be detached from the sensor insertiondevice 1 (see FIG. 11) by rotating the sensor insertion device 1 in onedirection of the circumferential direction D with respect to the baseplate 2. That is, the pair of leaf spring portions 32 are released fromthe pressure applied by the projection portion 61 a and are moved by therestoring force so as to be closer to each other in the perpendiculardirection C, and thus the opposing distance M becomes short comparedwith in the state where the sensor insertion device 1 and the base plate2 are attached (see FIG. 10). The pair of leaf spring portions 32 of theclamp portion 28 can clamp the proximal end side of the sensor 50extending to the outside of the living body by the restoring force. Inthe present exemplary embodiment, the optical fiber 51 of the sensor 50is clamped by the pair of leaf spring portions 32.

That is, when separating the sensor 50 and the base plate 2 from thesensor insertion device 1 and leaving the sensor 50 and the base plate 2on the living body side (see FIG. 7) after inserting the sensor 50 andthe needle portion 11 (see FIGS. 1 and 2) and pulling out the needleportion 11 (see FIG. 3) are completed by the sensor insertion assembly100, the clamp portion 28 of the base plate 2 clamps the sensor 50 alongwith a detaching operation from the sensor insertion device 1.Accordingly, the base pate 2, whose position is fixed on the surface ofthe living body by the adhesive portion 31 that will be described laterafter detachment of the sensor insertion device 1, clamps the portion ofthe sensor 50 extending to the outside of the living body, and thusmovement of the portion of the sensor 50 left in the living body to bepulled out of the living body due to body movement or the like of theperson to be measured can be suppressed.

More specifically, the pair of leaf spring portions 32 of the presentexemplary embodiment includes a first leaf spring 34 and a second leafspring 35 disposed so as to oppose the first leaf spring 34, and thefirst leaf spring 34 and the second leaf spring 35 are attached to anupper surface of the plate body portion 2 a. The first leaf spring 34includes an abutting portion 36 a that abuts and presses the sensor 50when clamping the sensor 50, a deformation portion 37 a that is integralwith or connected to the abutting portion 36 a and capable of changingthe position of the abutting portion 36 a in the perpendicular directionC by being elastically deformed, and a fixing portion 38 a that fixes afirst end of the deformation portion 37 a to the plate body portion 2 a.In addition, the second leaf spring 35 also includes an abutting portion36 b, a deformation portion 37 b, and a fixing portion 38 b similarly tothe first leaf spring 34.

The abutting portions 36 a and 36 b each include a recess portion 39that receives the sensor 50 when clamping the sensor 50. The recessportion 39 of each of the abutting portions 36 a and 36 b has anapproximately semicircular shape when the base plate 2 is viewed fromthe upper surface side (see FIGS. 10 and 11), and the sensor 50 isclamped by the recess portions 39 of the abutting portions 36 a and 36b. In the present exemplary embodiment, a distance between pointscorresponding to bottom positions of the recess portions 39 of theabutting portions 36 a and 36 b having semicircular shapes when the baseplate 2 is viewed from the upper surface side is set as the opposingdistance M described above (see FIGS. 10 and 11).

As illustrated in FIGS. 8 to 11, the deformation portion 37 a is a longplate-shaped member a first end of which is continuous with the abuttingportion 36 a and the second end of which is continuous with the fixingportion 38 a, and the first end side of the deformation portion 37 acontinuous with the abutting portion 36 a is capable of beingelastically deformed by using the position of the fixing portion 38 afixed to the plate body portion 2 a by a positioning portion 47 of theplate body portion 2 a and a screw 40 as a supporting point. Therefore,the position of the abutting portion 36 a in the nonstop direction C(see FIG. 1, etc.) can be changed by elastically deforming the first endside of the deformation portion 37 a continuous with the abuttingportion 36 a. With regard to this point, the same applies to thedeformation portion 37 b and the fixing portion 38 b of the second leafspring 35.

The spring regulating portions 33 are configured to regulate themovement of the pair of leaf spring portions 32 in the thicknessdirection of the plate body portion 2 a, and the spring regulatingportions 33 of the present exemplary embodiment are constituted byrectangular plate members. In addition, the spring regulating portions33 of the present exemplary embodiment are attached and fixed to theupper surface of the plate body portion 2 a in a state where the springregulating portions 33 are respectively in contact with the uppersurfaces of the abutting portions 36 a and 36 b so as to respectivelycover the upside of the abutting portion 36 a of the first leaf spring34 and the abutting portion 36 b of the second leaf spring 35.Specifically, the spring regulating portions 33 are fixed to the platebody portion 2 a by firmly engaging fixing projections 46 formed on theupper surface of the plate body portion 2 a with fixing holes defined inthe spring regulating portions 33 in the presence of the abuttingportions 36 a and 36 b between the spring regulating portions 33 and theplate body portion 2 a (see FIGS. 8 and 9).

An accommodation recess portion 45 that accommodates the pair of leafspring portions 32 and the spring regulating portions 33 is defined inthe center of the upper surface of the plate body portion 2 a of thepresent exemplary embodiment.

The joint portions 29 regulate the movement of the sensor insertiondevice 1 in the pulling-out direction B with respect to the base plate 2by engaging with the bottom plate portion 3 b (see FIG. 1, etc.) of thesensor insertion device 1 in the state where the base plate 2 isattached to the sensor insertion device 1 (see FIG. 10). In addition,the joint portions 29 permit the movement of the sensor insertion device1 in the pulling-out direction B with respect to the base plate 2 by notengaging with the bottom plate portion 3 b of the sensor insertiondevice 1 in the state where the base plate 2 is at a position at whichthe base plate 2 is detachable from the sensor insertion device 1 (seeFIG. 11).

Specifically, as illustrated in FIG. 8, the joint portions 29 of thepresent exemplary embodiment each include a trunk portion 41 provided soas to project upward (in the state where the base plate 2 is attached tothe sensor insertion device 1, in the same direction as the pulling-outdirection B) from the upper surface of the plate body portion 2 a and adistal end portion 42 that is formed so as to be continuous from thetrunk portion 41, is crooked at the distal end of the trunk portion 41and extends in the nonstop direction C.

By moving the trunk portions 41 and the distal end portions 42 in jointholes 43 defined in the bottom plate member constituting the bottomplate portion 3 b and in recess portions 44 (see FIG. 1 and so forth)that are defined in the lower surface of a flange portion 62 of ahousing body, which constitutes the bottom plate member together withthe bottom plate portion 3 b, and that communicate with the joint holes43, the attached state and detachable state of the sensor insertiondevice 1 and the base plate 2 can be switched.

The joint holes 43 formed in the bottom plate member constituting thebottom plate portion 3 b (see FIG. 1, etc.) each have a shape long inthe circumferential direction D when the bottom plate member is viewedfrom the upper surface side (see broken lines in FIGS. 10 and 11), andeach include, at a first end in the circumferential direction D, anattachment/detachment opening portion 43 a in which and from which thetrunk portion 41 and the distal end portion 42 are inserted and pulledout in attachment and detachment of the base plate 2. Theattachment/detachment opening portion 43 a has a large width (length inthe radial direction in FIGS. 10 and 11) compared with other portions ofthe joint hole 43. In addition, as illustrated in FIGS. 10 and 11, thelength of the joint portion 29 in the radial direction of the base plate2 when the base plate 2 is viewed from the upper surface side (in thepresent exemplary embodiment, equal to the length of the distal endportion 42) is smaller than the width of the attachment/detachmentopening portion 43 a of the joint hole 43 and is larger than the widthof the portions of the joint hole 43 other than theattachment/detachment opening portion 43 a.

In addition, as illustrated in FIG. 1, the recess portions 44 defined inthe flange portion 62 cover the upside of the joint holes 43 of thebottom plate member and each have a shape long in the circumferentialdirection D similarly to the joint holes 43. Further, the recessportions 44 each have a width approximately equal to theattachment/detachment opening portion 43 a, that is, a width larger thanthe length of the joint portions 29 in the radial direction of the baseplate 2 when the base plate 2 is viewed from the upper surface side,regardless of the position in the circumferential direction D.

Therefore, when joining the sensor insertion device 1 and the base plate2 (see FIG. 7) that are separated from each other, the distal endportions 42 of the joint portions 29 of the base plate 2 are inserted inthe attachment/detachment opening portions 43 a of the joint holes 43.Then, after the distal end portions 42 reach the positions of the recessportions 44, the distal end portions 42 of the joint portions 29 move inthe recess portions 44 and the trunk portions 41 of the joint portions29 move in the joint holes 43 in the circumferential direction D byrotating one of the base plate 2 and the sensor insertion device 1 inthe circumferential direction D with respect to the other. As a resultof the rotating operation, the positions of the joint portions 29 andthe attachment/detachment opening portions 43 a are displaced in thecircumferential direction D. Therefore, when it is attempted to move thesensor insertion device 1 in the pulling-out direction B with respect tothe base plate 2, the distal end portions 41 of the joint portions 29abut and thereby interfere with the bottom plate portion 3 b, and thusthe movement of the sensor insertion device 1 in the pulling-outdirection B is regulated by the joint portions 29. That is, this stateis the state where the base plate 2 is attached to the sensor insertiondevice 1 (see FIG. 10).

Conversely, when separating the sensor insertion device 1 and the baseplate 2 from each other in the state where the sensor insertion device 1and the base plate 2 are attached (see FIG. 10), one of the base plate 2and the sensor insertion device 1 is rotated in the circumferentialdirection D with respect to the other to cause the positions of thejoint portions 29 and the attachment/detachment opening portions 43 a tocoincide with each other in the circumferential direction D.Accordingly, the movement of the sensor insertion device 1 in thepulling-out direction B with respect to the base plate 2 is no longerregulated by the joint portions 29 because the distal end portions 41 ofthe joint portions 29 do not abut and thus not interfere with the bottomplate portion 3 b. That is, this state is the state where the base plate2 is at a position at which the base plate 2 is detachable from thesensor insertion device 1 (see FIG. 11). When separating the sensorinsertion device 1 and the base plate 2 after leaving the sensor 50 inthe living body, the sensor insertion device 1 is moved to the positionwhere the sensor insertion device 1 is detachable from the base plate 2via an operation of rotating the sensor insertion device 1 with respectto the base plate 2 in a state where the base plate 2 is pressed againstthe surface of the living body. Accordingly, according to the sensorinsertion assembly 100 of the present exemplary embodiment, a patient ora health care worker can perform, by operating one hand holding thesensor insertion device 1, a series of operations including pressing thebase plate 2 against the surface of the living body, rotating the sensorinsertion device 1 with respect to the base plate 2, and moving thesensor insertion device 1 in the pulling-out direction B to separate thesensor insertion device 1 from the base plate 2.

In the present exemplary embodiment, the attached state (see FIG. 10)and detachable state (see FIG. 11) of the sensor insertion device 1 andthe base plate 2 can be switched by relatively rotating one of thesensor insertion device 1 and the base plate 2 with respect to the otherin the circumferential direction D and changing the positionalrelationship between the attachment/detachment opening portions 43 a ofthe sensor insertion device 1 and the joint portions 29 of the baseplate 2 in the circumferential direction D. In addition, as describedabove, the engagement relationship between the pair of leaf springportions 32 and the cam portion 61 (in the present exemplary embodiment,the projection portion 61 a) changes along with the switching, and thusthe sensor 50 can be clamped by the elastic force of the pair of leafspring portions 32 by switching the state where the sensor insertiondevice 1 and the base plate 2 are attached to the state where these twoare detachable.

As described above, in the present exemplary embodiment, as a result ofperforming the rotating operation for separating the sensor insertiondevice 1 from the base plate 2 in the pulling-out direction B afterinserting the sensor 50 in the living body by using the sensor insertionassembly 100, the pair of leaf spring portions 32 of the clamp portion28 of the base plate 2 that move along with the rotating operation clampthe sensor 50 by an elastic force. However, the specific configurationfor realizing the attachment and detachment of a sensor insertion deviceand a base plate by relative rotating between these two and the specificconfiguration of a clamp portion that clamps a sensor along with therotating operation for detaching the base plate from the sensorinsertion device are not limited to the configuration of the presentexemplary embodiment, and can be realized by various configurations, forexample, by using screw connection for the attachment and detachment ofthe sensor insertion device and the base plate or using a moving memberthat moves without deformation and clamps the sensor along with therotating operation for detaching the base plate from the sensorinsertion device. In addition, although an operation of rotating one ofthe sensor insertion device 1 and the base plate 2 with respect to theother is performed as the operation for separating the sensor insertiondevice 1 from the base plate 2, and the clamp portion 28 that operatesalong with the rotating operation is used in the present exemplaryembodiment, for example, a clamp portion that clamps the sensor alongwith an operation of moving the sensor insertion device in thepulling-out direction with respect to the base plate may be used.However, since it is not required to secure an operation distance (inthe present exemplary embodiment, the length of the joint holes 43 inthe circumferential direction D) for switching the attached state anddetachable state of the sensor insertion device and the base plate inthe thickness direction of the base plate as a result of using a clampportion that operates along with the rotating operation as in thepresent exemplary embodiment, it becomes easy to design the base platewhose thickness in the pulling-out direction is thinner compared withthe case where the clamp portion is configured to operate along with themovement of the sensor insertion device in the pulling-out direction.

The sensor insertion device 1 separated from the base plate 2 afterleaving the sensor 50 is configured such that a user does not touch thedistal end of the needle portion 11. Specifically, the distal end of theneedle portion 11 is accommodated in the housing 3 so as not to projectto the outside from the bottom plate portion 3 b of the housing 3 (seeFIGS. 3, 6, and 7).

FIG. 12 is an enlarged view of a center portion of the base plate 2illustrated in FIG. 11. The second leaf spring 35 described above isconfigured to have a larger spring constant than the first leaf spring34, and, as illustrated in FIG. 12, the base plate 2 includes apositioning pin serving as the position regulating portion 30 thatregulates the position of the second leaf spring 35 when detaching thesensor insertion device 1. The positioning pin is omitted in FIGS. 8 to11 for the sake of convenience of description. In addition, in FIG. 12,the spring regulating portions 33 are indicated by broken lines for thesake of convenience of description.

The positioning pin serving as the position regulating portion 30 isprovided so as to project from the upper surface of the plate bodyportion 2 a, and abuts the abutting portion 36 b of the second leafspring 35 that moves so as to clamp the sensor 50 to regulate furthermovement of the abutting portion 36 b of the second leaf spring 35 whendetaching the sensor insertion device 1 and the base plate 2, that is,when performing an operation (see FIG. 10) of rotating the sensorinsertion device 1 in the circumferential direction D with respect tothe base plate 2 in the state where the sensor insertion device 1 andthe base plate 2 are attached. That is, the second leaf spring 35 havinga larger spring constant than the first leaf spring 34 is positioned bythe positioning pin, and the sensor 50 is clamped between the first leafspring 34 and the second leaf spring 35 as a result of the first leafspring 34 being pressed against the second leaf spring 35 positioned bythe positioning pin.

As described above, since a configuration in which the spring constantof the second leaf spring 35 is larger than the spring constant of thefirst leaf spring 34 and the second leaf spring 35 is positioned bycausing the second leaf spring 35 to the position regulating portion 30is employed in the present exemplary embodiment, the sensor 50 clampedbetween the first leaf spring 34 and the second leaf spring 35 can beclamped by the abutting portion 36 a of the first leaf spring 34 and theabutting portion 36 b of the second leaf spring 35 at a position of therecess portion 39 (see FIG. 9) of the abutting portion 36 b of thesecond leaf spring 35 abutting the position regulating portion 30. Thatis, since the second leaf spring 35 that abuts the position regulatingportion 30 functions to position the sensor 50 to be clamped, thevariation of the clamping position of the sensor 50 on the base plate 2can be suppressed. Particularly, in a sensor using an optical fiber,precise biological information can be obtained by suppressing thevariation of the clamping position of the sensor because signals arechanged by slight movement of the optical fiber left in the living body.

The adhesive portion 31 is provided on a surface opposing the surface ofthe living body, that is, the lower surface, of the base plate 2 so asto adhere on the surface of the living body such that the position ofthe base plate 2 on the surface of the body is less likely to be changedwhen inserting the sensor 50 by using the sensor insertion assembly 100and being separated from the sensor insertion device 1 and left on thesurface of the living body.

The adhesive portion 31 of the present exemplary embodiment isconstituted by a double-sided adhesive sheet including a first adhesivelayer that adheres on the lower surface of the base plate 2 and a secondadhesive layer that adheres on the surface of the living body, but isnot limited to this configuration. For example, the adhesive portion 31maybe configured in various ways such as by simply providing an adhesiveon the lower surface of the base plate 2 at positions other than theinsertion hole 70 to configure the adhesive portion 31. In addition, inthe case of configuring the adhesive portion 31 by the double-sidedadhesive sheet, a configuration in which the adhesive portion 31 isprovided on the whole area of the lower surface of the base plate 2 andis pierced through at the position of the insertion hole 70 wheninserting the sensor 50 and the needle portion 11 by using the sensorinsertion assembly 100 may be employed, and a configuration in which theadhesive portion 31 is stuck on the other part than the insertion hole70 on the lower surface of the base plate 2 may be alternativelyemployed.

As the adhesive used for the adhesive portion 31 that comes into contactwith the surface of the living body, for example, adhesives such asrubber-based adhesives, acrylic adhesives, and silicone-based adhesivesmay be used.

In addition, the other portions of the base plate 2 than the adhesiveportion 31 may be formed from the same material as the housing 3 of thesensor insertion device 1 described above.

As described above, the sensor insertion assembly 100 of the presentexemplary embodiment includes the sensor insertion device 1 thataccommodates the needle member 4 that is inserted in the living bodywith the sensor 50 capable of detecting biological information and ispulled out of the living body after leaving the distal end side of thesensor 50 in the living body and the base plate 2 that is detachablyattached to the sensor insertion device 1, and the base plate 2 isseparated from the sensor insertion device 1 and left on the living bodyside with the sensor 50 after leaving the sensor 50 in the living body.Moreover, the processing device capable of processing the biologicalinformation of the person to be measured detected by the sensor 50 isattached to the base plate 2 left on the surface of the living body, andit becomes possible to, for example, monitor temporal change in theblood glucose level of a diabetic patient for a predetermined period onthe basis of the biological information of the person to be measured.

The sensor insertion assembly and the base plate according to thepresent invention are not limited to the configuration of the exemplaryembodiment described above, and may be realized by variousconfigurations within the scope of what is described in Claims. Forexample, for the sensor insertion device 1, although the movable member7 is used as a plunger that is moved by the elastic force of theinsertion spring 5 a in insertion of the sensor 50 and the needleportion 11 in the living body, the movable member 7 may be configured tonot be moved in insertion of a sensor and a needle portion performed bythe urging force of a first urging member and to be moved in pulling outof the needle portion performed by the urging force of the second urgingmember.

The present disclosure relates to a sensor insertion assembly includinga sensor insertion device and a base plate and to the base plate, thesensor insertion device being configured to insert a sensor that detectsbiological information of a living body such as a patient in the livingbody.

REFERENCE NUMERAL LIST

1 sensor insertion device

2 base plate

2 a plate body portion

2 b peripheral wall portion

3 housing

3 a cylinder portion

3 b bottom plate portion

3 c top plate portion

4 needle member

5 first urging member

5 a insertion spring (first elastic member)

6 second urging member

6 a retrieving spring (second elastic member)

7 movable member

7 a cylinder portion

7 b flange portion

7 c deformation portion

7 d top plate portion

8 operation member

9 insertion hole of bottom plate portion

10 insertion hole of top plate portion

11 needle portion

12 connection portion

13 locked portion

14 insertion hole of connection portion

15 locking claw portion (locking portion)

16 receiving portion

17 connection portion

18 projection portion (locking portion)

19 rod portion

20 cutout

21 claw

22 projection

22 a lower surface of projection

23 pressing plate portion

24 claw

25 projection portion

26 pressing portion

27 tapered portion

28 clamp portion

29 joint portion

30 position regulating portion

31 adhesive portion

32 pair of leaf spring portions

33 spring regulating portion

34 first leaf spring

35 second leaf spring

36 a, 36 b abutting portion

37 a, 37 b deformation portion

38 a, 38 b fixing portion

39 recess portion

40 screw

41 trunk portion

42 distal end portion

43 joint hole

43 a attachment/detachment opening portion

44 recess portion

45 accommodation recess portion

46 fixing projection

47 positioning portion

50 sensor

51 optical fiber

60 engagement portion (locking release portion)

60 a projection portion

61 cam portion

61 a projection portion

62 flange portion

70 insertion hole

71 rubber member

100 sensor insertion assembly

A insertion direction

B pulling-out direction

C direction perpendicular to thickness direction of plate body portion

D circumferential direction

M opposing distance

O center axis line

What is claimed is:
 1. A sensor insertion assembly comprising: a sensorinsertion device comprising a needle member configured to be inserted ina living body together with a biological information sensor and to bepulled out of the living body after leaving a distal end side of thesensor in the living body; and a base plate detachably attached to afirst end side of the sensor insertion device, the base plate comprisinga clamp portion configured to move so as to clamp a proximal end side ofthe sensor extending to an outside of the living body after pulling outthe needle member and along with an operation of detaching the sensorinsertion device from the base plate, wherein the sensor insertiondevice is detachable from the base plate by being rotated with respectto the base plate.
 2. The sensor insertion assembly according to claim1, wherein the clamp portion includes first and second leaf springsconfigured to clamp the proximal end side of the sensor, and wherein thesensor insertion device includes a cam portion configured to change anengagement relationship with the first and second leaf springs alongwith rotation of the sensor insertion device with respect to the baseplate, and thereby change an amount of elastic deformation of the firstand second leaf springs.
 3. The sensor insertion assembly according toclaim 2, wherein: the second leaf spring is disposed so as to oppose thefirst leaf spring, a spring constant of the second leaf spring is largerthan a spring constant of the first leaf spring, and the base plateincludes a position regulating portion configured to regulate a positionof the second leaf spring when the base plate is detached from thesensor insertion device.
 4. The sensor insertion assembly according toclaim 3, wherein: an adhesive portion is disposed on a surface of thebase plate, the adhesive being adapted to adhere to the human bodyduring use of the sensor insertion assembly.
 5. The sensor insertionassembly according to claim 4, wherein the sensor comprises: a detectionportion configured to be left in the living body and configured todetect biological information, and an optical fiber, wherein thedetection portion is attached to a distal end portion of the opticalfiber, and wherein the optical fiber is configured to extend from thedetection portion to a location outside the living body during use ofthe sensor.
 6. The sensor insertion assembly according to claim 3,wherein the sensor comprises: a detection portion configured to be leftin the living body and configured to detect biological information, andan optical fiber, wherein the detection portion is attached to a distalend portion of the optical fiber, and wherein the optical fiber isconfigured to extend from the detection portion to a location outsidethe living body during use of the sensor.
 7. The sensor insertionassembly according to claim 2, wherein: an adhesive portion is disposedon a surface of the base plate, the adhesive being adapted to adhere tothe human body during use of the sensor insertion assembly.
 8. Thesensor insertion assembly according to claim 7, wherein the sensorcomprises: a detection portion configured to be left in the living bodyand configured to detect biological information, and an optical fiber,wherein the detection portion is attached to a distal end portion of theoptical fiber, and wherein the optical fiber is configured to extendfrom the detection portion to a location outside the living body duringuse of the sensor.
 9. The sensor insertion assembly according to claim2, wherein the sensor comprises: a detection portion configured to beleft in the living body and configured to detect biological information,and an optical fiber, wherein the detection portion is attached to adistal end portion of the optical fiber, and wherein the optical fiberis configured to extend from the detection portion to a location outsidethe living body during use of the sensor.
 10. The sensor insertionassembly according to claim 1, wherein: an adhesive portion is disposedon a surface of the base plate, the adhesive being adapted to adhere tothe human body during use of the sensor insertion assembly.
 11. Thesensor insertion assembly according to claim 10, wherein the sensorcomprises: a detection portion configured to be left in the living bodyand configured to detect biological information, and an optical fiber,wherein the detection portion is attached to a distal end portion of theoptical fiber, and wherein the optical fiber is configured to extendfrom the detection portion to a location outside the living body duringuse of the sensor.
 12. The sensor insertion assembly according to claim1, wherein the sensor comprises: a detection portion configured to beleft in the living body and configured to detect biological information,and an optical fiber, wherein the detection portion is attached to adistal end portion of the optical fiber, and wherein the optical fiberis configured to extend from the detection portion to a location outsidethe living body during use of the sensor.